Value Village / Clothing

What do people get wrong about washing swimwear?

This answer is a draft. It stays unpublished until legal review and source verification are complete.

The answerThe biggest misunderstanding is "swimwear is made for water, so it can go through a normal machine wash". The stretch fibre in swimwear (polyurethane, also sold as elastane or spandex) is damaged by chlorine, salt, the oils in sunscreen, heat and hard rubbing. The basic routine is: rinse in fresh water straight after use → hand-wash gently in a neutral detergent → press out the water in a towel → dry in the shade.

"It stretched after one season" and "the colour faded" are complaints heard everywhere in the world, and most of the time the cause is how the swimsuit was washed and dried. In Japan the three enemies of swimwear are well known: pool chlorine, sea salt and sunscreen.

What to go on

StepWhat to doWhy
Straight after useRinse in fresh water (at the pool or beach if you can)Removes chlorine, salt and sand. Do not leave it sitting wet
WashingPress-wash in lukewarm water (30°C / 86°F or below) with a neutral detergent (the "delicates" type, おしゃれ着用). In a machine: laundry net + gentle cycle + short programmePolyurethane is degraded by alkaline detergents, bleach and fabric softener
Removing waterPress between towels. Do not wring; keep the machine spin shortFibres stretch
DryingReshape and dry in the shade. No direct sun, no tumble dryerUV and heat fade the colour and weaken the stretch
StorageDry completely and store without sharp folds. Hangers stretch the shoulder straps, so lay it flat—
[Verify] The polyurethane degradation and lifespan figures are general guides based on textile-industry bodies and makers' information.

Misunderstanding 1|After the pool, just let it dry

Chlorine stays in the fibres after drying and keeps degrading them. Rinsing in fresh water the same day comes first.

Misunderstanding 2|Get rid of the chlorine smell with bleach

Bleach damages polyurethane. Wash in a neutral detergent and rinse thoroughly; that reduces the smell.

Misunderstanding 3|A tumble dryer is quicker and more hygienic

Heat destroys the stretch in polyurethane. Drying in the shade is quite enough; swimwear is thin and dries in a few hours.

Misunderstanding 4|Hanging it on a hanger dries it faster

A wet swimsuit on a hanger stretches the straps and the fabric. Dry it flat, or lay it on a towel.

Misunderstanding 5|Just carry the wet swimsuit home in a plastic bag

Sealed-in moisture starts mould and smell within a few hours. Rinse it, wrap it in a towel, and wash it as soon as you get home. If you use a plastic bag at all, keep it to the short trip home.

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Sources

https://www.caa.go.jp/policies/policy/representation/household_goods/guide/wash_02.html

https://www.qtec.or.jp/

https://www.jcfa.gr.jp/

⚠️ Editorial note: the source URLs above were identified by search. Our working environment cannot reach go.jp domains, so the contents have not been checked against the text. Verify every source before publication and record who checked it and when.

About this article

What we share here are ideas and everyday practices passed down among people living in Japan, together with general information drawn from public sources. They are not official recommendations, and they are not professional instruction. Practices vary between households and regions.

This is general information. Results vary from person to person and depend on your own conditions and surroundings.

Please decide for yourself, using your own judgement, whether any of this suits your situation. We cannot accept responsibility for any damage, loss or injury arising from following this article.

Follow the care label and the maker's instructions for any garment, shoe or bag. For expensive or sentimental items, ask a specialist cleaner or repairer.

Sources

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